Low sulphur fuel system utilizing coal char,and coproducts thereof

ABSTRACT

IN ACCORDANCE WITH THE DISCLOSURE OF THE PRESENT INVENTION IN ONE EMBODIMENT, COAL IN GRANULAR FORM IS HEATED AND INTRODUCED UNDER PRESSURE INTO A COAL DEVOLATILIZER FORMING A REACTION CHAMBER FOR THE COAL AND FROM WHICH REACTION BY-PRODUCTS ARE SEPARATELY WITHDRAWN. PREHEATED OIL ISINTRODUCED UNDER PRESSURE INTO AN OIL FLUID COKER FORMING A REACTION CHAMBER FOR THE OIL, AND FROM WHICH OIL REACTION PRODUCTS ARE SEPARATELY WITHDRAWN. GRANULAR RESIDUE FROM THE COAL DEVOLATILIZER AND OIL FLUID COKER ARE INTRODUCED UNDER PRESSURE INTO A HEAT GENERATOR IN WHICH FURTHER REACTION TAKES PLACE, THERE BEING MEANS FOR EFFECTING AN INTERCHANGE OF MATERIAL BETWEEN THE COAL DEVOLATILIZER AND THE HEAT GENERATOR, AND BETWEEN THE OIL FLUID COKER AND THE GENERATOR. THE BY-PRODUCTS FROM THE OIL FLUID COKER AND FROM THE COAL DEVOLATILIZER ARE SEPARATELY PROCESSED, AND THE DESULPHURIZED FUEL COMPONENTS THEREOF ARE USED WITH THE CARBONACEOUS PRODUCT, WHICH IS A COMBINED COAL CHAR AND OIL FLUID COKE, PRODUCED BY THE SYSTEM, WHEREBY TO PROVIDE A LOW SULPHUR FUEL SYSTEM, AND ALSO ELEMENTAL SULPHUR AND OTHER USEFUL BY-PRODUCTS WHICH MAY BE SEPARATELY UTILIZED. THE USE OF THE OIL FLUID COKER IS OPTIONAL, AND IN ONE FORM OF THE INVENTION THE OIL FLUID COKER COKER VESSEL IS USED AS A FURTHER PROCESSING VESSEL FOR DESULPHURIZING THE COAL, INTO WHICH HYDROGEN ISINTRODUCED TO FURTHER THE DESULPHURIZATION PROCESS.

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Wauw QUK QKNWU kewl q Sw mwi United States Patent O U.S. Cl. 44-1 R 15Claims ABSTRACT F THE DISCLSURE In accordance with the disclosure of thepresent invention in one embodiment, coal in granular form is heated andintroduced under pressure into a coal devolatilizer forming a reactionchamber for the coal and from which reaction by-products are separatelywithdrawn. Preheated oil is introduced under pressure into an oil fluidcoker forming a reaction chamber for the oil, and from which oilreaction products are separately withdrawn. Granular residue from thecoal devolatilizer and oil fluid coker are introduced under pressureinto a heat generator in which further reaction takes place, there beingmeans for effecting an interchange of material between the coaldevolatilizer and the heat generator, and between the oil fluid Cokerand the generator. The by-products Vfrom the oil fluid coker and fromthe coal devolatilizer are separately processed, and the desulphurizedfuel components thereof are used with the carbonaceous product, which isa combined coal char and oil fluid coke, produced by the system; wherebyto provide a low sulphur fuel system, and also elemental sulphur andother useful by-products which may be separately utilized. The use ofthe oil fluid coker is optional; and in one form of the invention theoil iluid coker vessel is used as a further processing vessel fordesulphurizing the coal, into which hydrogen is introduced to furtherthe desulphurization process.

This invention relates to the treatment and production of fuels, andcoproducts or by-products therewith, and concerns more specifically alow sulphur fuel system utilizing coal and oil, or coal alone, whereinthe fuel produced has greatly reduced sulphur content, compared with thesulphur content of the original coal and oil utilized in the system.

The application is a continuation-in-part of my prior application Ser.No. 801,460, tiled Feb. 24, 1969, now abandoned, which is in turn acontinuation-in-part of my prior application titled Process forProducing Combined Coal Char and Oil Coke, and Co-Products Therewith,Ser. No. 415,603, tiled Dec. 3, 1964, and now issued as Pat. No.3,437,562, dated Apr. 8, 1969.

In said prior copending application Ser. No. 415,603, now Pat. No.3,437,562, there is disclosed a process, and accompanying apparatus,wherein coal in granular form, and hydrocarbon oil, are introduced intoa system comprising a coal devolatilizer, an oil fluid coker, and a heatgenerator; whereby to provide a carbonaceous fuel which is a combinationof coal char and oil coke, and coproducts or by-products therewith whichmay be separately processed. As is pointed out in said copendingapplication, coal char has a lower sulphur content, as compared with thecoal from which it is made, whereas oil fluid coke may have a somewhathigher sulphur content as compared with the oil from which it isproduced. However, the carbonaceous fuel which is a combination of coalchar and oil coke will have a sulphur content which lies between but islower than the combination of the two individual components from whichit is produced. Thus if a coal having a relatively higher sulphurcontent is uti- "ice lized with oil having a relatively lower sulphurcontent, a combined coal char and oil coke may be produced which has aconsiderably lower sulphur content than the original coal. The processof said prior copending application thus inherently provides means, andmethods, for producing a carbonaceous fuel which is a combination ofcoal char and oil coke, and which has a lower sulphur content comparedwith the sulphur content of the original oil and coal of the system.Lower sulphur in relation to heat value further results from theelimination of moisture and moisture producing components, as will bemore particularly hereinafter described.

However, the amount of the sulphur reduction as above is dependent uponthe amount of oil used, which is generally the more expensive component,in relation to the coal; and it may be that the sulphur content of thecoal, or of the oil, or economic considerations, dictate thedesirability of further sulphur reduction to minimize sulphur dioxide(SO2) emission in the burning of the fuel; whereby to reduce airpollution, and comply with municipal regulations concerning the emissionof sulphur dioxide into the atmosphere.

In accordance with the present invention, in one embodiment thereof, thebasic process of the prior copending application is used, but furthermeans and methods are provided for the reduction of sulphur in theresulting fuel; whereby to permit the utilization of coal having arelatively high sulphur content which otherwise cannot be used withoutexcessive atmospheric pollution. Specifically in accordance with thepresent invention, pressurization is used within the coal devolatilizerand the oil fluid coker, wherein it has been found that suchpressurization increases the interaction between hydrogen and sulphur,effecting increased extraction of the sulphur from the coal and from theoil. Further, in accordance with the present invention, the fuelcomponents of the coproducts or lay-products of the system aredesulphurized, and then combined with or utilized with the carbonaceousfuel, which is the combined coal char and oil coke, in a manner toproduce a combined fuel which has a greatly reduced sulphur content ascompared with the oil and coal which form the charging components forthe system. In this manner means and methods are provided for utilizingoil and coal, and particularly the latter, which are eX- cessive or highin sulphur content, and thus may not be used without excessive sulphurdioxide emission and air pollution. Still further, the coproduct orby-product recovery, in accordance with the system of the presentinvention, which includes the recovery of elemental sulphur, providesfor by-product utilization and economic advantages which are materiallyenhanced, as compared for example with the attempted recovery andutilization of SO2 as a single by-product from the vastly greatervolumes of waste furnace stack gases.

The combination of the coproducts or by-products of the system, with thechar, whereby to provide a low sulphur combined fuel, and thepressurization features of the present invention, are useful in a systemutilizing coal alone, and such a system is shown in one embodiment. Insuch embodiment hydrogen is introduced into contact with the char tofurther the desulphurization process.

It is accordingly an object of the present invention to provide atreatment and production method for fuels, to produce a carbonaceousfuel which is a combination of coal char and oil coke, or coal alone,and wherein pressure is utilized during the processing in a manner toreduce the sulphur content of the resulting fuel, and hydrogen isapplied to the carbonaceous fuel to further the desulphurizationprocess.

A further object of the invention is to provide a process for theproduction of fuel, which includes the production of a carbonaceous fuelwhich is a combination of coal char and oil coke, or coal char alone,and wherein the fuel components of the produced coproducts or byproductsare desulphurized and then used with the carbonaceous fuel, in a mannerto provide a maximum of heat energy in relation to the sulphur contentof the fuel.

A still further object of the invention is to provide in a fuelproducing system, as above set forth, for the separation and utilizationof by-products or coproducts produced from the coal and from the oil;which may be recovered and utilized for maximum economic worth.

Various other objects, advantages and features of the invention will beapparent from the following specification when taken in connection withthe accompanying drawings, wherein certain preferred embodiments of theinvention are set forth for purposes of illustration.

FIG. 1 illustrates an embodiment utilizing coal and oil; and

IFIG. 2 sets forth an embodiment utilizing coal alone.

Referring more particularly to the drawings, in the embodiment of IFIG.1, the fuel processing apparatus comprises, generally, a coaldevolatilizer 10, an oil fluid coker 12 and a heat generator 14. Coal,together with steam, fuel gas `or other lluidizing media is introducedinto the coal devolatilizer, under pressure, through a supply conduit16. By way of illustration, the coal may preferably be bituminous coal,of a particle size for example eight mesh and smaller down to relativelyfine particles, and it may be either coking or non-coking in character.The introduction of the coal and the tluidizing media is under thecontrol of a valve, as indicated at 18. Within the coal devolatilizerthe coal is processed and coal char is formed.

As stated, the coal and fluidizing media are introduced into the supplyconduit 16 under pressure, and during the processing, in accordance withthe present invention, the coal devolatilizer and the heat generator andthe oil .tluid coker, are all maintained under the same relatively highpressure, which as will be presently pointed out, increases theextraction yof sulphur from the material being processed, particularlyin the reactions which occur within the coal devolatilizer and the oilfluid coker. There does not appear to be criticality in any particularpressure, viz, as the pressure is increased the extraction of sulphur isincreased; and accordingly the pressure within the coal devolatilizer10, the oil lluid coker 12, and the heat generator 14 may be as much as1500 pounds per square inch, or more. However, in a preferredernbodiment the pressure may be on the order of 150 to 200 pounds persquare inch, which, it has been found, effects a material increase insulphur extraction, as compared with non-pressurized operation; while atthe same time avoiding very high pressures which increase the cost offabrication of the pressure vessels. As will be understood, in a fullscale commercial installation, these may be one hundred feet or more inheight.

Preheated oil under pressure is delivered from a supply line 20, undercontrol of a pair of valves 22 and 24, to a pair of spray heads oratomizers 26 and 28, disposed within the oil fluid coker 12. The oilsupplied may be any suitable hydrocarbon mineral oil. Examples are oilfrom crude oil wells or tar sands or oil shale, or asphalt, either innatural form or from which one or more fractions have been removed suchas reduced crude or Bunker C oil. The oil may also be obtained from theprocessing of coal or other carbonaceous materials such as lignite, orpeat and the like. The oil will be selected in accordance with theeconomics of the particular location of the apparatus. Within the fluidcoker the oil is cracked, and a generally granular lluid coke or char isproduced.

Preheated air under pressure is supplied from a line 30, under controlof a valve 32 leading to the heat generator 14, and this lineinterconnects with a line 34 under control of a. valve 36 leading fromthe, bottoni of the cil fluid coker, by means of which the oil iluidcoke or reaction product within the oil fluid coker is withdrawn andintermixed with the preheated air in the line 30 and delivered into thebottom of the heat generator 14.

A steam line for steam under pressure, as indicated at 38, controlled bya valve 40, is provided leading into the bottom of the oil fluid coker,to aid in tluidizing the char bed within the iluid coker, andmaintaining agitation therein.

Char from the heat generator is returned to the oil fluid coker througha pair of conduits 42 and 44, under control of valves 46 and 48; theconduits 42 and 44, and the conduits 30 and 34 thus providing forinterchange of char between the oil fluid coker and the heat generatorin a continuous circulation.

In a similar manner continuous circulation or interchange of charbetween the coal devolatilizer and the heat generator is provided. Tothis end, a conduit 50, under control of a valve 52, is provided at thelower end of the heat generator, interconnecting with the coal supplyline 16, in a manner so that char is supplied from the heat generatorinto the coal devolatilizer, along with the incoming raw coal.Similarly, the lower end of the coal devolatilizer is provided with aconduit 54, under control of a valve 56, which conduit interconnectswith a supply line 5S, under control of a valve 60 for preheated airunder pressure, leading to the lower portion of the heat generator 14.By this means char and reaction products are continuously interchangedbetween the heat generator and the coal devolatilizer, through conduits50 and 16, and conduits 54 and 58, providing continuous circulation.

A steam line, as indicated at 62, for steam under pressure, leads to thelower end of the heat generator, to control the temperature therein, andto maintain proper agitation of the ttluidized char bed. Steam line 62may be controlled by a valve 64, as will be understood.

The preheated air introduced into the heat generator through theconduits 30 and 58, effects a partial burning of the char producttherein, thus supplying heat for the operation of the system. In anillustrative embodiment the temperature within the heat generator may bemaintained in the range of 1200-1250 F., with the temperature within theoil iluid coker and the coal devolatilizer being maintained in the rangeof 900-950 F.

In order to preclude the improper flow of gases downwardly through theconduit 34, at the bottom of the oil uid coker, there is provided avalve controlled stripping device, as indicated at 66, into which steamis supplied under pressure so as to sweep the gases upwardly, throughthe vessel 12, and to preclude downward flow through the conduit 34.Such steam under pressure also aids in uidizing the char bed within theoil uid coker. In a similar manner conduits 42 and 44 are provided withpressure steam stripping devices, as indicated at 68 and 70; conduit 50at the lower end of the heat generator is supplied with a strippingdevice 72; and conduit 54 at the lower end of the coal devolatilizer isprovided with a pressure steam stripping device 74.

As is pointed out in the copending application to which reference hashereinbefore been made, in a system constituted as hereinbeforedescribed, the continuous interchanger of granular carbonaceous materialbetween the coal devolatilizer and the heat generator and the oil fluidcoker, with the processing of the material within the coal devolatilizerand the oil fluid coker with heat supplied by the heat generator, andthe further processing of the material within the heat generator,produces a granular carbonaceous fuel, the individual particles of whichcomprise a combination of coal char and oil fluid coke. The carbonaceousgranular fuel thus produced, may be withdrawn from any of the threevessels, but in the embodiment herein shown, it is withdrawn from thebottom of the coal devolatilizer by means of a conduit 76, under controlof the valve 78. Conduit 76 leads to the combuss tion chamber 80, of afurnace 82, as shown.

In accordance with the present invention, as heretofore set forth, asuitable high pressure is maintained within the coal devolatilizer 10,the heat generator 14, and the oil fluid coker 12, which may be on theorder of 150- 200 p.s.i. on up to 1500 p.s.i., or more, if the strengthcapacity of the vessels so permits. Hydrogen is formed during theprocessing operation, and it has been found that the elevated pressurematerially increases the interaction between the hydrogen and thesulphur in the coal, and in the oil, particularly in the coaldevolatilizer and the oil uid coker, whereby the carbonaceous fuelproduct produced has a materially lower sulphur content. The reactedhydrogen and sulphur are withdrawn and transmitted to the byproduct orcoproduct recovery system, which will now be described.

AByproducts or coproducts are exh'austed or withdrawn from the top ofthe oil fluid coker through an exhaust line 84, under control of a valve86, leading to a gasoline and gas oil recovery system, which may be ofany conventional character, designated diagrammatically at 88. From therecovery system the gas oil is directed through a valve controlledexhaust line 90, the gasoline is directed to a valve controlled exhaustline 92, and the fuel gas, olens, and the like are directed by means ofa valve controlled exhaust line 94 to a sulphur recovery systerndiagrammatically designated at 96. The fuel gas from the oil fluid cokermay contain carbon monoxide, hydrogen, methane, ethane, propane, andhydrogen sulde; and the olefins may comprise ethylene, propylene,butylene, etc., as will be understood. The sulphur recovery system maybe any conventional type such, for example, as the diethanolamine-Clauseprocess or other suitable high temperature acceptor system. From thesulphur recovery system elemental sulphur is withdrawn or dischargedthrough a valve controlled discharge line 98, v

whereas the olefins, LPG (liquid petroleum gases) and fuel gas, aredirected through a valve controlled discharge line 100 into an olefin,LPG and fuel gas separation system, of any conventional type,diagrammatically indicated by the reference numeral 102.

Referring to the heat generator 14, the gases discharged or withdrawnfrom the upper end thereof will be primarily gases of combustion, and asshown, these are discharged from the heat generator through a valvecontrolled discharge line 104 to a steam generator, diagrammaticallydesignated as 106, wherein the primary heat of the combustion gases isextracted and used for the generation of steam used elsewhere in thesystem as heretofore described. Air to insure complete combustion of thegases is introduced into line 104 from an air supply line 108 controlledby a valve 109.

From the steam generator the combustion gases are discharged through apair of valve controlled conduits, as indicated at 110 and 112, leadingrespectively to heat exchangers 114 and 116, for further heating theincoming air in lines and 58; after which the combustion gases are ledrespectively to exhaust lines 118 and 120, and thereafter to suitablescrubbing devices (not shown) and exhausted into the atmosphere. Ininstances wherein sufficient heat is extracted in the steam generator sothat the gases cannot be advantageously used in the heat exchanger, thegases may be vented from lines 110 and 112 through exhaust lines 111 and113.

Referring to the coal devolatilizer 10, the coproducts or byproductsdischarged therefrom, at the upper end, through a valve controlledexhaust conduit 122, pass into a tar recovery system, of anyconventional type, designated by the reference numeral 124. The tarproduct from the tar recovery system leads to a valve controlleddischarge line 126, as shown, whereas the fuel gas is directed through avalve controlled discharge line 128 to the sulphur recovery system 96.

In accordance with the present invention, the tar product, which is lowin sulphur, may be led into the furnace combustion chamber through acombustion supply line,

as indicated at 130, or if market conditions so warrant, the tar productmay be discharged through a valve controlled discharge line 132 to beused for other industrial purposes, such for example in the treatment ofopen hearth steel, etc.

Referring further to the olefin, LPG, and fuel gas separation system102, it will be seen that the fuel gas component is delivered from thisseparation system to the combustion chamber of the furnace through avalve controlled discharge line or conduit 134, whereas the otherdischarge products such as ethylene (02H4) and propylene (C3H6) andpropane (CaHg) and butanes (C4-) may be individually discharged through=valve controlled discharged lines, as shown, or directed by valvecontrolled bypass lines into a valve controlled conduit 136 leading tothe combustion chamber of the furnace 82. As in the case of the tarproduct, market conditions will dictate whether these components are tobe burned, or to be separately discharged for other industrial uses.

It is important to note that the fuel gas, and the other dischargeproducts of the olefin, LlPG, and fuel gas separation system, areessentially sulphur-free, by reason of the sulphur extraction in thesulphur recovery system 96.

It will be seen that in accordance with the present invention, means andmethods are provided for producing furnace fuel of kgreatly reducedsulphur content, as compared with the sulphur content of the coal andoil supplied, and from which the fuel is produced. By way of example, alow cost coal having a sulphur content so high that it cannot be used asa furnace fuel, in accordance with municipal requirements, and withoutundue pollution of the atmosphere by sulphur dioxide, may be combinedwith oil, having a lower sulphur content, whereby to produce by suchcombination a combined coal char and oil fluid coke of reduced sulphurcontent, compared with the sulphur content of the original chargingingredients. In accordance with the invention, the high pressure in thecoal devolatilizer 10, and in the oil fluid coker 12, and in the heatgenerator 14, further reduces the sulphur content of the granularcarbonaceous fuel produced, by the increased interaction betweenhydrogen and sulphur, particularly in the oil fluid coker and the coaldevolatilizer. This sulphur appears in the fuel gas, and in the olefinsand the like transmitted to the sulphur recovering system whereinelemental sulphur is extracted and recovered for industrial use. Theessentially sulphur-free fuel gas, and optionally the other hydrocarbonsrecovered in the separation system, may then be transmitted to thecombustion chamber of the furnace, along with the essentiallysulphur-free tar product from the coal devolatilizer whereby, and byreason of the system thus provided, a maximum of heat energy is providedby the coal and oil, with a minimum of sulphur, or as it may beexpressed, a minimum number of pounds of sulphur emission to theatmosphere, per million B.t.u.s.

As previously mentioned, due to the elimination of moisture from thecombined carboneous fuel, rand due to the elimination of hydrogen, theformation of moisture in combustion is minimized, thus providingminimized heat loss due to moisture and increased heat value in relationto the sulphur present; further reducing the sulphur content per millionB.t.u.s of available heat.

The value of the recovered co-product or by-products essentially offsetsthe cost of the separation system.

As will be understood, the use of the oil Huid coker in the system isoptional. To this end it will be noted that the oil uid coker can be cutoff completely from the system by manipulation of the valves in thevarious pipe lines, thus to utilize the coal devolatilizer and the heatgenerator, in the manner therefore described, and for the purposesheretofore set forth. When the oil fluid coker is thus not utilized, theadvantages owing from the use of oil in the system are not obtained; buta sulphur reduction is nevertheless secured, in the manner heretoforeset forth, as compared with the sulphur content of the coal supplied tothe system.

In FIG. 2 an embodiment of the invention is set forth, utilizing coalalone, and wherein the oil fluid coker vessel is replaced by a vesselfor further processing the coal, so as to effect a further removal ofthe sulphur therefrom.

Referring to FIG. 2, the coal devolatilizer a and the heat generator 14aare provided, functioning in the manner heretofore described. In placeof the oil fluid Coker, and interconnected with the heat generator inthe manner previously described, there is provided a vessel indicated bythe reference numeral 150, and designated as a desulphurizerf Referringto FIG. 2, the raw coal is introduced into the coal devolatilizer bymeans of a pipe line, indicated as 16a, as in the embodiment previouslydescribed. From the coal devolatilizer the coal or char is transmittedto the heat generator 14a by means of conduits 54a and 58a, as in theembodiment previously described. From the heat generator the coal orchar is transmitted to the desulphurizer 150 through conduits 42a and44a, also as previously set forth.

The processed coal, in the form of char, is withdrawn from thedesulphurizer by means of a conduit 152, under control of a valve 154,for transmission to the combustion chamber of the furnace.

The entire system preferably is pressurized, as in the previouslydescribed embodiment. The temperature within the coal devolatilizer maybe maintained within the range of 800 F. to 1000 F. Within the heatgenerator the temperature may be maintained within the range l000 F. tol200 F., by reason of the partial burning of the coal or char whichtakes place therein; and within the desulphurizer the temperature may bemaintained within the range of l300 F. to 1700 F.

The higher temperature range within the desulphurizer is obtained, inthe embodiment set forth, by a reaction of hydrogen with the coal char,within the desulphurizer chamber. To this end, hydrogen is introducedinto the desulphurizer by means of a conduit or pipe line 156, leadinginto the lower section of the chamber, to aid in maintaining a iluidizedbed, along with the stripping medium and the steam introduced throughthe pipe line 38a. The hydrogen pipe line 156 passes through a heatexchanger 158 through which the char exhaust conduit 152 also passes,and wherein the hydrogen gases will be heated from the exhaust char.

The exhaust gases from the desulphurizer, which will compriseessentially fuel gas containing H2S, CO, CH4 and H2, are transmitted bymeans of a conduit or pipe line 160 to the pipe line 128a which leadsfrom the tar recovery system 124a of the coal devolatilizer; fortransmission to the sulphur recovery system, as previously described,and as indicated by the reference numeral 96a. From the sulphur recoverysystem the elemental sulphur is recovered through conduit 98a, whereasthe gases are transmitted through the conduit 100a to a gas separator,as indicated at 162. Within a gas separator, which may be ofconventional type, the H2, containing CO, is transmitted by means of apipe line 164 to the hydrogen supply line 156; excess fuel gas beingtransmitted by the conduit, as indicated by the reference numeral 134a,to the combustion chamber of the furnace. Makeup hydrogen is introducedinto conduit 156 from a supply line 166, and a pump or blower asindicated at 168 is provided in pipe line 156 to insure a freecirculation of the gases therethrough.

It will be seen that the combined fuel transmitted to the furnace has agreatly reduced sulphur content, as compared with the sulphur content ofthe original coal. Within the coal devolatilizer, at elevated pressure,the H2 which is formed extracts sulphur from the char, with the exhaustfrom the coal devolatilizer being transmitted to the tar recovery system124a, as previously described.

The tar product which is transmitted to the furnace through the conduit126a will be essentially sulphur-free. Within the desulphurizer, atelevated pressure, at elevated temperature, the hydrogen introducedthrough conduit 156, along with such additional hydrogen as is extractedfrom the char within the desulphurizer, combines with the sulphur toform H2S, and effect a further removal of sulphur from the char. Thechar, with greatly reduced content is then transmitted to the furnacethrough conduit |152, whereas the H2S and other components of the fuelgas are transmitted from the desulphurizer to the sulphur recoverysystem 96a, whereby the fuel gas transmitted to the furnace forcombustion, through conduit 134a is essentially sulphur-free. As in thepreviously described embodiment, the combined fuel transmitted to thefurnace will have greatly reduced sulphur content as compared with thesulphur content of the original coal.

While in the drawings the various reaction chambers are indicated asseparate vessels, it will be understood that the chambers may be formed,if desired, as individual chambers within a single vessel.

It is obvious that various changes may be made in the particularembodiments set forth for purposes of illustration, without departingfrom the spirit of the invention. The invention is accordingly not to belimited to the particular embodiments shown and described, but only asindicated in the following claims.

The invention is hereby claimed as follows:

1. The method of producing granular carbonaceous product which comprisesseparately subjecting coal and oil in predetermined proportions to theaction of heat and pressure on the order of p.s.i. or more todevolatilize the coal and crack the oil, and thereafter furtherprocessing a mix of the coal and oil to provide a carbonaceous productof relatively low sulphur content the individual particles of whichcomprise combined coal char and oil fluid coke.

2. The method of producing a granular carbonaceous product whichcomprises introducing coal into a first chamber, subjecting the coaltherein to the action of heat and pressure on the order of 150 p.s.i. ormore to devolatilize the coal and produce a coal char, introducing oilinto a second chamber, subjecting the oil therein to the action of heatand pressure on the order of 150 p.s.i. or more to crack the oil andproduce a fluid coke, and subjecting a mix of the char and the fluidcoke to the action of heat to provide a carbonaceous product theindividual particles of which comprise combined coal char and oil fluidcoke.

3. The method of producing a granular carbonaceous product as defined inclaim 2 wherein the coal char, oil fluid coke, and carbonaceous productare continuously recirculated between said chambers.

4. The method of producing fuel from coal and oil which comprisesseparately subjecting coal and oil in predetermined proportions to theaction of heat to devolatilize the coal and crack the oil, reacting thehydrogen thereby produced with the sulphur in the coal and oil toprovide a sulphur-containing fuel gas, further processing a mix of thecoal and oil to provide a carbonaceous product the individual particlesof which comprise combined coal char and oil fluid coke, removing thesulphur from the fuel gas, and combining the carbonaceous product andthe fuel gas to provide a relatively low sulphur furnace fuel.

5. The method of producing fuel as defined in claim 4 wherein the coaland oil are subjected to the action of heat under pressure of at leastseveral atmospheres.

6. Apparatus for producing a granular carbonaceous product whichcomprises a rst chamber, means for pressurizing said chamber to apressure on the order of 150 p.s.i. or more, and means for supplyingcoal thereto, means for supplying heat thereto to devolatilize the coaland produce a coal char, a second chamber, means for pressurizing thesecond chamber to a pressure on the Order 0f 150 PS-- 0r more. means.for introducing oil product as defined in claim 6 wherein conduit meansis provided connected to each of said chambers for withdrawingby-products therefrom.

I8. Apparatus for producing a granular carbonaceous product whichcomprises a first chamber, means for pressurizing said chamber to apressure on the order of 150 p.s.i. or more, and means for supplyingcoal thereto, means for supplying heat thereto to devolatilize the coaland produce a coal char, a second chamber, means for pressurizing thesecond chamber to a pressure on the order of 150 p.s.i. or more, meansfor inrtducing oil into said second chamber, means for supplying heat tothe second chamber to crack the oil therein to produce a fluid coke, athird chamber, means for maintaining pressure on the order of 150 p.s.i.or more therein, and means for introducing the coal char and oil fluidcoke therein, and means for supplying heat to the mix within the thirdchamber to thereby provide a relatively low sulphur carbonaceous productthe individual particles of which comprise combined coal char and oilfluid coke.

9. Apparatus for producing fuel which comprises a first chamber, meansfor supplying coal thereto, means for supplying heat thereto todevolatilize the coal and produce a coal char, means for reactinghydrogen with said coal char to form a sulphur-containing fuel gas, asecond chamber, means for introducing oil into said second chamber,means for supplying heat to the second chamber to crack the oil thereinand produce a iiuid coke, means for reacting hydrogen with the fluidcoke in said second chamber to provide a sulphur-containing fuel gas,means for further processing the coal char and oil fluid coke to form acarbonaceous product the individual particles of which comprise coalchar and oil fluid coke, means for removing sulphur from the fuel gas,and means for combining and delivering the sulphurfree fuel gas andcarbonaceous product to a common combustion system.

10. Apparatus for producing fuel as defined in claim 9 wherein means isprovided for pressurizing said chambers to a pressure of at leastseveral atmospheres.

11. The method of producing fuel froincoal which comprises subjectingthe coal to heat to devolatilize the coal, reacting the hydrogen therebyproduced with the sulphur in the coal to provide a sulphur-containingfuel gas further processing the coal to form a coal char, extractingsulphur from the char during said further processing, extracting thesulphur from the fuel gas, and combining the fuel gas and char toprovide a relatively low sulphur furnace fuel.

I12. The method of producing fuel from coal as defined in claim 11wherein the further processing of the coal comprises a partial burningthereof.

13. The method of producing fuel from coal as defined in claim 12wherein the further processing of the coal comprises subjecting the coalto the action of hydrogen at elevated temperature to effect thedesulphurization thereof.

14. The method of producing fuel from coal which comprises introducingthe coal into a first chamber, subjecting the coal to the action of heatin said chamber to effect a partial desulphurization thereof,introducing the coal into a second chamber, effecting a partial burningof the coal in said second chamber, introducing the coal into a thirdchamber, and subjecting the Coal to the action of hydrogen at elevatedtemperature in said third chamber to effect a further desulphurizationof the coal.

15. The method of producing fuel from coal as defined in claim 14wherein the hydrogen is processed to remove sulphur therefrom, and thenrecirculated to said third chamber for further reaction with the coal.

References Cited UNITED STATES PATENTS 1,972,944 9/1934 Morrell 208--81,986,593 1/ 1935 Morrell 208-8 2,640,016 5/ 1953 Martin 201-222,895,904 7/ 1959 Jones et al. 201--31 2,950,231 8/ 1960 Batchelor etal. 201-17 3,437,562 4/ 1969 Singh 201-22 3,640,016 2/1972 Lee et al44-1 R CARL F. DEES, Primary Examiner U.S. Cl. X.R.

